A Slavic form of the Norse name Ingvarr, meaning warrior or protected by Ing.
Igor arrived in the Slavic world through the Vikings. The Old Norse name Ingvarr — composed of "Ing," the name of a Norse god associated with fertility and the earth, and "varr," meaning watchful or careful — was carried eastward by the Varangian traders and warriors who established the Rus principalities in the 9th century. As the name settled into East Slavic phonology, Ingvarr became Igor, and it entered the ruling dynasties of Kievan Rus so thoroughly that it became one of the quintessential Russian, Ukrainian, and Eastern European names.
Igor of Kiev, a 10th-century Varangian prince and early ruler of the Rus, cemented the name in the historical imagination. The name's cultural reach expanded dramatically through art and literature. Alexander Borodin's unfinished opera Prince Igor (premiered posthumously in 1890) brought the medieval Rus warrior-prince to concert halls across Europe, its famous "Polovtsian Dances" becoming one of the most recognizable orchestral pieces in the repertoire.
Then Igor Stravinsky — perhaps the most influential composer of the 20th century, whose Rite of Spring detonated a revolution in Western music in 1913 — gave the name an association with radical artistic genius that has never fully faded. For much of the 20th century in the English-speaking world, Igor suffered from its association with the hunchbacked laboratory assistant of horror film cliché, a figure whose name became a shorthand for grotesque servility. But that cultural residue has steadily thinned, and Igor has regained its footing as a name with genuine historical grandeur — princely, Norse in origin, bearing the weight of a millennium of Slavic civilization and some of the greatest music ever composed.